1 /* 2 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/stackMapFrame.hpp" 27 #include "classfile/verifier.hpp" 28 #include "memory/resourceArea.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "oops/symbol.hpp" 31 #include "runtime/handles.inline.hpp" 32 #include "utilities/globalDefinitions.hpp" 33 34 StackMapFrame::StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* v) : 35 _offset(0), _locals_size(0), _stack_size(0), 36 _stack_mark(0), _flags(0), _max_locals(max_locals), 37 _max_stack(max_stack), _verifier(v) { 38 Thread* thr = v->thread(); 39 _locals = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_locals); 40 _stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_stack); 41 int32_t i; 42 for(i = 0; i < max_locals; i++) { 43 _locals[i] = VerificationType::bogus_type(); 44 } 45 for(i = 0; i < max_stack; i++) { 46 _stack[i] = VerificationType::bogus_type(); 47 } 48 } 49 50 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) { 51 Thread* thr = _verifier->thread(); 52 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1); 53 StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0, _max_locals, _max_stack, _locals, stack, _verifier); 54 return frame; 55 } 56 57 void StackMapFrame::initialize_object( 58 VerificationType old_object, VerificationType new_object) { 59 int32_t i; 60 for (i = 0; i < _max_locals; i++) { 61 if (_locals[i].equals(old_object)) { 62 _locals[i] = new_object; 63 } 64 } 65 for (i = 0; i < _stack_size; i++) { 66 if (_stack[i].equals(old_object)) { 67 _stack[i] = new_object; 68 } 69 } 70 if (old_object == VerificationType::uninitialized_this_type()) { 71 // "this" has been initialized - reset flags 72 _flags = 0; 73 } 74 } 75 76 VerificationType StackMapFrame::set_locals_from_arg( 77 const methodHandle m, VerificationType thisKlass, TRAPS) { 78 SignatureStream ss(m->signature()); 79 int init_local_num = 0; 80 if (!m->is_static()) { 81 init_local_num++; 82 // add one extra argument for instance method 83 if (m->name()->equals(vmSymbols::object_initializer_name()) && 84 thisKlass.name()->not_equals(vmSymbols::java_lang_Object())) { 85 _locals[0] = VerificationType::uninitialized_this_type(); 86 _flags |= FLAG_THIS_UNINIT; 87 } else { 88 _locals[0] = thisKlass; 89 } 90 } 91 92 // local num may be greater than size of parameters because long/double occupies two slots 93 while(!ss.at_return_type()) { 94 init_local_num += _verifier->change_sig_to_verificationType( 95 &ss, &_locals[init_local_num], 96 CHECK_VERIFY_(verifier(), VerificationType::bogus_type())); 97 ss.next(); 98 } 99 _locals_size = init_local_num; 100 101 switch (ss.type()) { 102 case T_OBJECT: 103 case T_ARRAY: 104 { 105 Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type())); 106 // Create another symbol to save as signature stream unreferences 107 // this symbol. 108 Symbol* sig_copy = 109 verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(), 110 CHECK_(VerificationType::bogus_type())); 111 assert(sig_copy->equals(sig), "symbols don't match"); 112 return VerificationType::reference_type(sig_copy); 113 } 114 case T_INT: return VerificationType::integer_type(); 115 case T_BYTE: return VerificationType::byte_type(); 116 case T_CHAR: return VerificationType::char_type(); 117 case T_SHORT: return VerificationType::short_type(); 118 case T_BOOLEAN: return VerificationType::boolean_type(); 119 case T_FLOAT: return VerificationType::float_type(); 120 case T_DOUBLE: return VerificationType::double_type(); 121 case T_LONG: return VerificationType::long_type(); 122 case T_VOID: return VerificationType::bogus_type(); 123 default: 124 ShouldNotReachHere(); 125 } 126 return VerificationType::bogus_type(); 127 } 128 129 void StackMapFrame::copy_locals(const StackMapFrame* src) { 130 int32_t len = src->locals_size() < _locals_size ? 131 src->locals_size() : _locals_size; 132 for (int32_t i = 0; i < len; i++) { 133 _locals[i] = src->locals()[i]; 134 } 135 } 136 137 void StackMapFrame::copy_stack(const StackMapFrame* src) { 138 int32_t len = src->stack_size() < _stack_size ? 139 src->stack_size() : _stack_size; 140 for (int32_t i = 0; i < len; i++) { 141 _stack[i] = src->stack()[i]; 142 } 143 } 144 145 // Returns the location of the first mismatch, or 'len' if there are no 146 // mismatches 147 int StackMapFrame::is_assignable_to( 148 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const { 149 int32_t i = 0; 150 for (i = 0; i < len; i++) { 151 if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) { 152 break; 153 } 154 } 155 return i; 156 } 157 158 bool StackMapFrame::has_flag_match_exception( 159 const StackMapFrame* target) const { 160 // We allow flags of {UninitThis} to assign to {} if-and-only-if the 161 // target frame does not depend upon the current type. 162 // This is slightly too strict, as we need only enforce that the 163 // slots that were initialized by the <init> (the things that were 164 // UninitializedThis before initialize_object() converted them) are unused. 165 // However we didn't save that information so we'll enforce this upon 166 // anything that might have been initialized. This is a rare situation 167 // and javac never generates code that would end up here, but some profilers 168 // (such as NetBeans) might, when adding exception handlers in <init> 169 // methods to cover the invokespecial instruction. See 7020118. 170 171 assert(max_locals() == target->max_locals() && 172 stack_size() == target->stack_size(), "StackMap sizes must match"); 173 174 VerificationType top = VerificationType::top_type(); 175 VerificationType this_type = verifier()->current_type(); 176 177 if (!flag_this_uninit() || target->flags() != 0) { 178 return false; 179 } 180 181 for (int i = 0; i < target->locals_size(); ++i) { 182 if (locals()[i] == this_type && target->locals()[i] != top) { 183 return false; 184 } 185 } 186 187 for (int i = 0; i < target->stack_size(); ++i) { 188 if (stack()[i] == this_type && target->stack()[i] != top) { 189 return false; 190 } 191 } 192 193 return true; 194 } 195 196 bool StackMapFrame::is_assignable_to( 197 const StackMapFrame* target, bool is_exception_handler, 198 ErrorContext* ctx, TRAPS) const { 199 if (_max_locals != target->max_locals()) { 200 *ctx = ErrorContext::locals_size_mismatch( 201 _offset, (StackMapFrame*)this, (StackMapFrame*)target); 202 return false; 203 } 204 if (_stack_size != target->stack_size()) { 205 *ctx = ErrorContext::stack_size_mismatch( 206 _offset, (StackMapFrame*)this, (StackMapFrame*)target); 207 return false; 208 } 209 // Only need to compare type elements up to target->locals() or target->stack(). 210 // The remaining type elements in this state can be ignored because they are 211 // assignable to bogus type. 212 int mismatch_loc; 213 mismatch_loc = is_assignable_to( 214 _locals, target->locals(), target->locals_size(), THREAD); 215 if (mismatch_loc != target->locals_size()) { 216 *ctx = ErrorContext::bad_type(target->offset(), 217 TypeOrigin::local(mismatch_loc, (StackMapFrame*)this), 218 TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target)); 219 return false; 220 } 221 mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD); 222 if (mismatch_loc != _stack_size) { 223 *ctx = ErrorContext::bad_type(target->offset(), 224 TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this), 225 TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target)); 226 return false; 227 } 228 229 bool match_flags = (_flags | target->flags()) == target->flags(); 230 if (match_flags || is_exception_handler && has_flag_match_exception(target)) { 231 return true; 232 } else { 233 *ctx = ErrorContext::bad_flags(target->offset(), 234 (StackMapFrame*)this, (StackMapFrame*)target); 235 return false; 236 } 237 } 238 239 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) { 240 if (_stack_size <= 0) { 241 verifier()->verify_error( 242 ErrorContext::stack_underflow(_offset, this), 243 "Operand stack underflow"); 244 return VerificationType::bogus_type(); 245 } 246 VerificationType top = _stack[--_stack_size]; 247 bool subtype = type.is_assignable_from( 248 top, verifier(), false, CHECK_(VerificationType::bogus_type())); 249 if (!subtype) { 250 verifier()->verify_error( 251 ErrorContext::bad_type(_offset, stack_top_ctx(), 252 TypeOrigin::implicit(type)), 253 "Bad type on operand stack"); 254 return VerificationType::bogus_type(); 255 } 256 return top; 257 } 258 259 VerificationType StackMapFrame::get_local( 260 int32_t index, VerificationType type, TRAPS) { 261 if (index >= _max_locals) { 262 verifier()->verify_error( 263 ErrorContext::bad_local_index(_offset, index), 264 "Local variable table overflow"); 265 return VerificationType::bogus_type(); 266 } 267 bool subtype = type.is_assignable_from(_locals[index], 268 verifier(), false, CHECK_(VerificationType::bogus_type())); 269 if (!subtype) { 270 verifier()->verify_error( 271 ErrorContext::bad_type(_offset, 272 TypeOrigin::local(index, this), 273 TypeOrigin::implicit(type)), 274 "Bad local variable type"); 275 return VerificationType::bogus_type(); 276 } 277 if(index >= _locals_size) { _locals_size = index + 1; } 278 return _locals[index]; 279 } 280 281 void StackMapFrame::get_local_2( 282 int32_t index, VerificationType type1, VerificationType type2, TRAPS) { 283 assert(type1.is_long() || type1.is_double(), "must be long/double"); 284 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 285 if (index >= _locals_size - 1) { 286 verifier()->verify_error( 287 ErrorContext::bad_local_index(_offset, index), 288 "get long/double overflows locals"); 289 return; 290 } 291 bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK); 292 if (!subtype) { 293 verifier()->verify_error( 294 ErrorContext::bad_type(_offset, 295 TypeOrigin::local(index, this), TypeOrigin::implicit(type1)), 296 "Bad local variable type"); 297 } else { 298 subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK); 299 if (!subtype) { 300 /* Unreachable? All local store routines convert a split long or double 301 * into a TOP during the store. So we should never end up seeing an 302 * orphaned half. */ 303 verifier()->verify_error( 304 ErrorContext::bad_type(_offset, 305 TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)), 306 "Bad local variable type"); 307 } 308 } 309 } 310 311 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) { 312 assert(!type.is_check(), "Must be a real type"); 313 if (index >= _max_locals) { 314 verifier()->verify_error( 315 ErrorContext::bad_local_index(_offset, index), 316 "Local variable table overflow"); 317 return; 318 } 319 // If type at index is double or long, set the next location to be unusable 320 if (_locals[index].is_double() || _locals[index].is_long()) { 321 assert((index + 1) < _locals_size, "Local variable table overflow"); 322 _locals[index + 1] = VerificationType::bogus_type(); 323 } 324 // If type at index is double_2 or long_2, set the previous location to be unusable 325 if (_locals[index].is_double2() || _locals[index].is_long2()) { 326 assert(index >= 1, "Local variable table underflow"); 327 _locals[index - 1] = VerificationType::bogus_type(); 328 } 329 _locals[index] = type; 330 if (index >= _locals_size) { 331 #ifdef ASSERT 332 for (int i=_locals_size; i<index; i++) { 333 assert(_locals[i] == VerificationType::bogus_type(), 334 "holes must be bogus type"); 335 } 336 #endif 337 _locals_size = index + 1; 338 } 339 } 340 341 void StackMapFrame::set_local_2( 342 int32_t index, VerificationType type1, VerificationType type2, TRAPS) { 343 assert(type1.is_long() || type1.is_double(), "must be long/double"); 344 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 345 if (index >= _max_locals - 1) { 346 verifier()->verify_error( 347 ErrorContext::bad_local_index(_offset, index), 348 "Local variable table overflow"); 349 return; 350 } 351 // If type at index+1 is double or long, set the next location to be unusable 352 if (_locals[index+1].is_double() || _locals[index+1].is_long()) { 353 assert((index + 2) < _locals_size, "Local variable table overflow"); 354 _locals[index + 2] = VerificationType::bogus_type(); 355 } 356 // If type at index is double_2 or long_2, set the previous location to be unusable 357 if (_locals[index].is_double2() || _locals[index].is_long2()) { 358 assert(index >= 1, "Local variable table underflow"); 359 _locals[index - 1] = VerificationType::bogus_type(); 360 } 361 _locals[index] = type1; 362 _locals[index+1] = type2; 363 if (index >= _locals_size - 1) { 364 #ifdef ASSERT 365 for (int i=_locals_size; i<index; i++) { 366 assert(_locals[i] == VerificationType::bogus_type(), 367 "holes must be bogus type"); 368 } 369 #endif 370 _locals_size = index + 2; 371 } 372 } 373 374 TypeOrigin StackMapFrame::stack_top_ctx() { 375 return TypeOrigin::stack(_stack_size, this); 376 } 377 378 void StackMapFrame::print_on(outputStream* str) const { 379 str->indent().print_cr("bci: @%d", _offset); 380 str->indent().print_cr("flags: {%s }", 381 flag_this_uninit() ? " flagThisUninit" : ""); 382 str->indent().print("locals: {"); 383 for (int32_t i = 0; i < _locals_size; ++i) { 384 str->print(" "); 385 _locals[i].print_on(str); 386 if (i != _locals_size - 1) { 387 str->print(","); 388 } 389 } 390 str->print_cr(" }"); 391 str->indent().print("stack: {"); 392 for (int32_t j = 0; j < _stack_size; ++j) { 393 str->print(" "); 394 _stack[j].print_on(str); 395 if (j != _stack_size - 1) { 396 str->print(","); 397 } 398 } 399 str->print_cr(" }"); 400 }